摘要:
The crystalline dihydrochloride of a specific cephalosporin derivative is stable to heat and retains its antibacterial activity even after storage over long periods at high temperature. The crystalline dihydrochloride can be obtained by removing protective groups from the cephalosporin derivative wherein the amino group and carboxy groups are protected and then crystallizing the cephalosporin derivative from a hydrochloric acid aqueous solution. The crystalline dihydrochloride is useful for pharmaceutical preparations.
摘要:
A crystalline substance of Cefditoren pivoxyl is provided which has a high purity and enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving an amorphous form of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous form well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg/ml to 250 mg/ml of Cefditoren pivoxyl dissolved in the alkanol alone. From the latter solution, crystals of Cefditoren pivoxyl are induced to deposit by addition of water at a temperature of 0-10° C. The resulting admixture of the concentrated solution of Cefditoren pivoxyl in alkanol with added water and the deposited Cefditoren pivoxyl is then agitated 10° C. or below, to effect a complete crystallization of Cefditoren pivoxyl.
摘要:
As a novel substance is provided such a new, crystalline substance of Cefditoren povoxyl which has a high purity and an enhanced thermal stability on storage. This crystalline Cefditoren pivoxyl may be prepared by a process comprising a step of dissolving amorphous substance of Cefditoren pivoxyl in an anhydrous, first organic solvent capable of dissolving said amorphous substance well therein, and steps of replacing the first organic solvent component of the resulting solution by an anhydrous alkanol of 1 to 5 carbon atoms as a second organic solvent, in such a manner that the firstly prepared solution of Cefditoren pivoxyl in the first organic solvent is mixed with a volume of the alkanol and then is concentrated below 15° C. under reduced pressure, and so on. Thereby, the process proceeds so as to produce a solution containing 50 mg/ml to 250 mg/ml of Cefditoren pivoxyl dissolved in the alkanol alone. From the latter solution, crystals of Cefditoren pivoxyl are induced to deposit by addition of water at a temperature of 0-10° C. The resulting admixture of the concentrated solution of Cefditoren pivoxyl in alkanol with added water and the deposited Cefditoren pivoxyl is then agitated 10° C. or below, to effect a complete crystallization of Cefditoren pivoxyl.
摘要:
Processes are provided for the preparation of orally administrable, yellow and powdery compositions essentially consisting of particles composed of a homogeneous mixture of an amorphous Cefditoren pivoxil substance with a water soluble high-molecular additive. These compositions can be produced by dissolving crystalline Cefditoren pivoxil substance and the water-soluble high-molecular additive in an aqueous solution of an acid, then neutralizing the resultant solution, to co-precipitate the product, and drying the thus precipitated product, followed by recovering the product in the form of the above-mentioned particles.
摘要:
Processes are provided for the preparation of orally administrable, yellow and powdery compositions essentially consisting of particles composed of a homogeneous mixture of an amorphous Cefditoren pivoxil substance with a water soluble high-molecular additive. These compositions can be produced by dissolving crystalline Cefditoren pivoxil substance and the water-soluble high-molecular additive in an aqueous solution of an acid, then neutralizing the resultant solution, to co-precipitate the product, and drying the thus precipitated product, followed by recovering the product in the form of the above-mentioned particles.
摘要:
Cephalosporin compounds, intermediate compounds therefor, and processes for preparation thereof are described; the compounds have the formula (I) ##STR1## wherein R.sub.1 and R.sub.2 can each represent hydrogen, a hydroxyl group, a lower alkoxy group, or a substituted or unsubstituted phenylalkoxy group; R.sub.3 represents hydrogen or a lower alkyl group; R.sub.4 represents hydrogen or a hydroxyl group; and R.sub.5 represents ##STR2## wherein R.sub.6 is hydrogen, a lower alkyl group, an aminoalkyl group, an aminoaralkyl group, a --(CH.sub.2).sub.n --SO.sub.3 Na group, or a --(CH.sub.2).sub.n --COR.sub.9 group [wherein R.sub.9 is a hydroxyl group, an OM group (wherein M is an alkali metal), an alkoxy group, or an ##STR3## group, (wherein R.sub.10 and R.sub.11, which may be the same or different, can represent hydrogen or an alkyl group), and n is 0 or an integer of from 1 to 4]; R.sub.7 is hydrogen, a lower alkyl group, an amino group, or a substituted or unsubstituted aryl group; and R.sub.8 represents hydrogen or a lower alkyl group; or, a pharmaceutically acceptable salt thereof.
摘要:
Penicillin compounds and methods for the production thereof are described, said penicillin compounds being represented by the formula (I) ##STR1## wherein R.sub.1, R.sub.2, and R.sub.3 each represents hydrogen, a lower alkyl group, a halogen atom, a lower alkoxy group, a hydroxyl group, or a substituted or unsubstituted phenylalkoxy group except that R.sub.1, R.sub.2, and R.sub.3 cannot all represent hydrogen simultaneously; R.sub.4 represents hydrogen or a lower alkyl group; and R.sub.5 represents hydrogen or a hydroxyl group.
摘要:
In a color image forming apparatus provided with a photoreceptor having a rotatable peripheral surface; plural sets of a charging device, an imagewise exposure device, and a developing device, each set of the plural sets is provided separately from other sets around the peripheral surface of the photoreceptor so that plural color component images are formed one after another by the plural sets and are superimposed so as to form a color image on the peripheral surface during a single rotation of the peripheral surface. The developing device has a casing and the imagewise exposure device and the developing device of each set are arranged such that a portion on the peripheral surface locating at an imagewise exposing position moves into the casing of the developing device before the electric potential V1 of the portion is lowered to the half of V1 (V1/2). A pre-transfer exposing device/transfer device and pre-cleaning exposing device/cleaning device all operate such that the potential on the photoreceptor moves into the casings of the transfer device or cleaning device before the potential is lowered to half its value.
摘要:
An image forming apparatus has an image forming body which is rotatable in a subsidiary scanning direction. A plurality of imagewise exposure devices for imagewise exposing the image forming body are arranged to face the image forming body and to be aligned in a straight line in a primary scanning direction perpendicular to the subsidiary scanning direction of the image forming body. A common supporting member is provided for supporting the plurality of exposure devices, and bearing members are provided on first and second ends of the common supporting member. The plurality of exposure devices are: (i) radially arranged on the common supporting member with respect to a rotation axis of the image forming body, and (ii) fixed on the supporting member with respect to the bearing members, and the image forming body is rotatable against the common supporting member through the bearing members.
摘要:
An image forming apparatus including: an image forming section to form a toner image on a recording sheet; a fixing device which has a fixing roller, an endless fixing belt trained with a tension about at least two rollers including the fixing roller, a heating device to heat the endless fixing belt, and a pressure roller to press the fixing roller through the endless belt, wherein the fixing device fixes the toner image on the recording sheet at a nip portion formed between the heated endless fixing belt and the pressure roller; a tension changing section to change the tension of the endless fixing belt; a recording sheet discriminating section to discriminate a type of recording sheet to be used; and a controller controling to make the tension changing section to change the tension of the fixing belt corresponding to the type of recording sheet.